Abstract:

The effect of adding different concentration gradients of p-hydroxybenzyl alcohol to the culture medium of Grifola
frondosa on mycelial growth and the production of extracellular polysaccharide in submerged fermentation. Meanwhile, we
determined changes in mycelial growth, reducing sugar (residual sugar) content, extracellular polysaccharide content, pH,
p-hydroxybenzyl alcohol and gastrodin contents in the fermentation broth of Grifola frondosa, and we also made a dynamic
analysis. Results showed that addition of 200 mg/L p-hydroxybenzyl alcohol was found to be optimal, resulting in an
increase in mycelial biomass of 22.73% and an increase in extracellular polysaccharide production of 10.24% as compared
with the control group without added p-hydroxybenzyl alcohol; both increases were significant (P < 0.05). Dynamic analysis
results showed that the growth of Grifola frondosa remained stable from day 8 onwards; glucose was consumed as the carbon
source, and residual glucose and the production of extracellular polysaccharide both remained stable from day 10 onwards.
In addition, the gastrodin content increased as a result of partial conversion of p-hydroxybenzyl alcohol into gastrodin.

Key words: p-hydroxybenzyl alcohol, Grifola frondosa, extracellular polysaccharide, biomass, fermentation kinetics